The invention relates to a four-door motor vehicle having a door sealing system for frameless doors, the body of which motor vehicle has on both sides a front and a rear door cutout and, between them, a B pillar which ends level with the window sill, wherein the door cutouts are bordered by a primary seal. Motor vehicles with frameless doors (coupés or convertibles) have been designed to date with two doors because a number of problems which arise in the case of four doors were considered insurmountable. The free end of the B pillar level with the window sill requires special stiffening and sealing measures.
The sealing is difficult because a row of sealing points has to be formed between moveable parts: in the form of a primary seal between the door cutout of the body and the doors, in the form of a secondary seal between the mutually facing end surfaces of the two doors, in the form of window channel seals between the windows (of course frameless) and the doors, and at the free upper end of the B pillar. All of the sealing points come together at said end. A further problem arises in that the lowerable windows, in the raised state, tightly adjoin each other in a sealing manner because of the lack of the upper part of a B pillar, but, in the lowered state, have to be at a distance from each other in the longitudinal direction in order to be able to be entirely accommodated by the door.
All of these problems have to meet the exacting impermeability requirements applicable in modern motor vehicle manufacturing.